US5268093A

Movatterモバイル変換

Info

Publication number: US5268093A
Application number: US07/879,093
Authority: US
Inventors: Richard D. Hembree; Brian F. Sullivan
Original assignee: Recovery Engineering Inc
Current assignee: KATADYN HOLDING AG
Priority date: 1990-04-05
Filing date: 1992-05-01
Publication date: 1993-12-07
Anticipated expiration: 2010-12-07

Abstract

Description

This is a continuation of application Ser. No. 07/503,635, filed Apr. 5, 1990.

TECHNICAL FIELD

Broadly, the invention relates to water purification systems. Specifically, the invention relates to portable water purification systems which include both a filter for physically removing particulate contaminants and larger pathogens from the water and a porous body of biocidally effective material for chemically disinfecting the water.

BACKGROUND

Sources of fresh water are often contaminated with disagreeable suspended solids and/or harmful pathogens including parasites such as schistosoma, cysts such as Giardia, bacteria such as cholera and viruses such as hepatitis.

Various methods are available for producing potable water from fresh water sources contaminated with suspended solids and/or pathogens. Selection of the most appropriate method requires assessment and balancing of the output requirements, energy availability, and size restrictions.

The most constraining situation in the design of a purification system is the design of a readily transportable system capable of microbiologically purifying water contaminated with both larger pathogens such as cysts (about 6 microns in diameter) which are resistant to chemical disinfection and smaller pathogens such as viruses (about 0.05 microns in diameter) which are difficult to filter.

One method employed to microbiologically purify contaminated water attempts to chemically disinfect the water by dissolving a biocide into the water or percolating the water through a biocidally active porous resin. Exemplary of the chemical disinfection method are U.S. Pat. Nos. 4,151,092 and 4,298,475.

U.S. Pat. No. 4,151,092, issued to Grimm et al., discloses a portable water purification system that includes (i) a supply of biocidally effective tablets, (ii) a first container for retaining a supply of contaminated water treated with the biocide disinfectant, (iii) a second container sealingly receivable within the first container for exerting pressure upon the treated water contained within the first container when forced downward into the first container, and (iv) a replaceable filter cartridge coupled to the base of the second container for filtering the treated water retained within the first container as the water is forced from the first container into the second container. The filter cartridge includes a polyethylene filter to remove suspended solids, a layer of activated carbon to remove the biocide and other distasteful contaminants, and a layer of felt to retain the activated carbon. While generally effective, chemical disinfection requires that the contaminated water be treated for upwards of thirty minutes with the biocide prior to removal of the biocide by passage through the activated carbon and/or consumption of the water.

U.S. Pat. No. 4,298,475, issued to Gartner, discloses a portable water purification system operable by mouth suction which comprises a straw sequentially containing filter media for removing suspended solids form the water, biocidally active anion exchange resin for chemically disinfecting the water, filter media for further removing suspended solids, activated carbon for removing distasteful contaminants including residual disinfecting chemical, and filter media for retaining the activated carbon. Gartner does not discuss the pore sizes of the filter medias.

A second method employed to microbiologically purify contaminated water attempts to filter the pathogens from the contaminated water employing a microfilter. While this method can be effective for removing the larger pathogens such as cysts and bacteria, such systems are generally ineffective for removing the smaller pathogens such as viruses, require significant operating energy, produce modest quantities of filtered water, and require frequent filter replacement.

Accordingly, a substantial need exists for a simple and efficient, manually operable, portable, water purification system that can produce significant quantities of microbiologically purified water with minimal effort.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of the invention in compacted storage form.

FIG. 2 is a cross-sectional front view of the invention embodiment depicted in FIG. 1 taken along line 2--2.

FIG. 3 is a cross-sectional view of the invention embodiment depicted in FIG. 2 in operational form.

FIG. 4 is a cross-sectional view of the first container portion of the invention embodiment depicted in FIG. 2.

FIG. 5 is a cross-sectional view of the plunger portion of the invention embodiment depicted in FIG. 2.

FIG. 6 is a logarithmic micron scale indicating the sizes of various particles.

SUMMARY

A manually operable apparatus for producing potable water from contaminated water which includes (i) a first container having an open end and an outlet orifice, (ii) a filter operably positioned within the first container for filtering contaminated water placed within the first container as the contaminated water is forced out of the first container through the outlet orifice, (iii) a porous body of biocidally effective material operably positioned within the first container for disinfecting contaminated water placed within the first container as the contaminated water is forced out of the first container through the outlet orifice, and (iv) a plunger sealably receivable within the first container through the open end for forcing contaminated water retained within the first container through the filter and the porous body of biocidally effective material and out of the first container through the outlet orifice.

The apparatus further includes (i) a means for abating the formation of a vacuum within the first chamber as the plunger is withdrawn from the first container, (ii) a nozzle in hinged communication with the outlet orifice in the first container for sealing the outlet orifice when placed in a first position and directing the flow of potable water flowing out of the first container through the outlet orifice when placed in a second position, and (iii) a second container having an open end which is operable as a drinking cup for the potable water generated by the system and as a cover for the first container.

DEFINITIONS

As utilized herein, the phrases "microbiologically purified" and "microbiological purification", when used in connection with microbiologically contaminated water, means sufficient removal and/or deactivation of potentially harmful cysts, bacteria and viruses so as to render the water microbiologically potable.

DETAILED DESCRIPTION OF ONE EMBODIMENT OF THE INVENTION INCLUDING A BEST MODEConstruction

The invention is a compact, manually operable, portable water purification system capable of producing significant quantities of potable water.

The system will be described with respect to the invention embodiment depicted in FIGS. 1-5 wherein common reference numbers are maintained throughout the Figures in accordance with the Nomenclature established above.

Referring to FIGS. 1 through 3, thesystem 10 includes (i) a cylindricalfirst container 20 which accommodates afilter 80 and a porous body of biocidallyeffective material 90 and is operable for retaining a quantity of contaminatedwater 101 to be purified, (ii) a cylindricalsecond container 40 operable as a cover for thefirst container 20 and as a receptacle for retaining thepotable water 103 generated by thesystem 10, and (iii) acylindrical plunger 50 telescopingly and sealingly receivable within thefirst container 20 for forcing contaminatedwater 101 retained within thefirst container 20 through thefilter 80 and the porous body of biocidallyeffective material 90 accommodated within thefirst container 20.

Referring to FIG. 4, thefirst container 20 defines a cylindricalfirst chamber 30 which is subdivided into anupper portion 30a and alower portion 30b by an upper horizontalannular flange 24 which changes the diameter of the cylindricalfirst chamber 30. Theupper portion 30a of thefirst chamber 30 has a smaller diameter than thelower portion 30b of thefirst chamber 30.

Thefirst container 20 also includes a lower horizontalannular flange 25 immediately below the upper horizontalannular flange 24 which further increases the diameter of thelower portion 30b of thefirst chamber 30. The upper 24 and lower 25 horizontal annular flanges divide thecontainer sidewall 23 into anupper sidewall section 23a between thetop 21 of thefirst container 20 and the upper horizontalannular flange 24, amiddle sidewall section 23b between the upper 24 and a lower 25 horizontal annular flanges, and alower sidewall section 23c between the lower horizontalannular flange 25 and thebottom 22 of thefirst container 20.

Acylindrical baffle 26 extends vertically within thefirst chamber 30 from the upperhorizontal flange 24 to proximate thebottom 22 of thefirst container 20. Thebaffle 26 terminates above thebottom 22 of thefirst container 20 so as to define an annular passage 34 around thebaffle 26.

Thefilter 80 accommodated within thefirs container 20 is cylindrical in shape and positioned inside thebaffle 26. The top 81 andbottom 82 of thefilter 80 are sealingly coupled to the upper horizontalannular flange 24 and thebottom 22 of thefirst container 20 respectively. Thefilter 80 andbaffle 26 separate thelower portion 30b of thefirst chamber 30 into (i) a centralcylindrical cavity 31 defined by thefilter 80, (ii) an innerannular cavity 32 defined by thefilter 80 and thebaffle 26, and (iii) an outerannular cavity 33 defined by thebaffle 26 and thelower section 23c of thesidewall 23.

Theinner surface 83 of thefilter 80 is substantially vertically aligned with the inner surface of theupper portion 30a of thefirst container 30 so as to provide a substantially continuous surface to reduce the space provided between the sidewall of theplunger 50 and the sidewall of thefirst container 20 and the interior surface of thefilter 80.

A firstannular screen 27 is positioned within the outerannular cavity 33 in abutment with the lower horizontalannular flange 25 and separates the outerannular cavity 33 into anupper portion 33a and alower portion 33b. Theupper portion 33a of the outerannular cavity 33 is defined by the upper horizontalannular flange 24, themiddle section 23b of thefirst container sidewall 23, thebaffle 26, and the firstannular screen 27. Thelower portion 33b of the outerannular cavity 33 is defined by the firstannular screen 27, thelower section 23c of thefirst container sidewall 23, thebaffle 26, and thebottom 22 of thefirst container 20.

Anoutlet orifice 35 for theupper portion 33a of the outerannular cavity 33 extends through the upperhorizontal flange 24.

Thelower portion 33b of the outerannular cavity 33 is packed with a layer of porous biocidallyactive material 90 and optionally with one or more layers of anactive component 95 such as a layer of activated carbon for removing molecules which contribute undesired taste and odor, a layer of a chelating agent to remove hardness ions, and the like. Thefirst screen 27 prevents the biocidallyeffective material 90 and/or optional active component(s) 95 from flowing out of thefirst container 20 through theoutlet orifice 35 along with the purified water ***.

Thefilter 80,baffle 26,screen 27, and biocidallyeffective material 90 may be retained within a replaceable cartridge (not shown) which is threadably engageable within thelower portion 30b of thefirst chamber 30 so as to sealingly contact the upperhorizontal flange 24. The bottom of the cartridge (not shown) would form thebottom 22 of thefirst container 20 while the sides of the cartridge (not shown) would define a double sidewall with thelower section 23c of thefirst container sidewall 23.

Anozzle 70 is hingedly coupled to thefirst container 20 at the upperhorizontal flange 24 and placed in fluid communication with theoutlet orifice 35 in thefirst container 20. Theproximal end 71 of thenozzle 70 is rounded so as to permit hinged rotation of thenozzle 70 about theoutlet orifice 35 in thefirst container 20 while permitting theproximal end 71 of thenozzle 70 to seal theoutlet orifice 35 in thefirst container 20 when positioned parallel to thefirst container 20. Sealing of theoutlet orifice 35 in thefirst container 20 prevents deactivation of the biocidallyeffective material 90 by preventing thematerial 90 from drying out.

Thenozzle 70 has aninlet orifice 74 proximate theproximal end 71 of thenozzle 70 and anoutlet orifice 75 proximate thedistal end 72 of thenozzle 70. Apassageway 73 extends through thenozzle 70 and connects theinlet 74 andoutlet 75 orifices. Theinlet orifice 74 is configured so that theorifice 74 aligns with theoutlet orifice 35 in thefirst container 20 when thenozzle 70 is positioned to extend substantially transversely to thefirst container 20. Theoutlet orifice 75 is configured so that purifiedwater 103 exits thenozzle 70 in a downward fashion.

Referring to FIG. 3, thesecond container 40 has anopen top 41 and is configured for use as a cover for thefirst container 20 and as a receptacle for thepotable water 103 generated by thesystem 10. An inwardly extending annular rib 46 is provided on thesidewall 43 of thesecond container 40 proximate the top 41 of thesecond container 40. The rib 46 is compatible with anannular notch 36 in themiddle section 23b of thefirst container sidewall 23 for securing thesecond container 40 over thefirst container 20. Thesecond container 40 is sized to provide a gap between theupper sidewall section 23a of thefirst container 20 and thesidewall 43 of thesecond container 40 which is sufficient to accommodate thenozzle 70 when thenozzle 70 is positioned parallel to thefirst container 20.

Referring to FIG. 5, theplunger 50 is configured to be telescopically received within theupper portion 30a of thefirst chamber 30 and the centralcylindrical cavity 31 subdivision of thelower portion 30b of thefirst chamber 30. Accordingly, the body of theplunger 50 is constructed as a right circular cylinder with a diameter slightly smaller than the smaller of the diameter of theupper portion 30a of the first chamber and the diameter of thecentral cavity 31. Theproximal end 51 of theplunger 50 is capped with ahead 54 which provides a smooth, flat surface against which the palm of the hand may be comfortably placed for forcing theplunger 50 into thefirst container 20 and applying pressure to the supply of contaminatedwater 101 retained within thefirst container 20. Theplunger 50 defines anupper chamber 56 and alower chamber 57. Anupper orifice 58 extends through thesidewall 53 of theplunger 50 proximate theproximal end 51 of theplunger 50 for providing access from theupper chamber 56 to the atmosphere. Amiddle orifice 59 connects theupper chamber 56 and thelower chamber 57. Alower orifice 60 extends through thedistal end 52 of theplunger 50 for providing access from thefirst chamber 30 defined by thefirst container 20 into thelower chamber 57 defined by theplunger 50. The combination of upper 56 and lower 57 chambers along with the interconnecting upper 58, middle 59, and lower 60 orifices provide a continuous passage from thefirst chamber 30 to the atmosphere.

Acheck valve 55, comprising a free-floating disc with several holes extending through the periphery of the disc, is configured within thelower chamber 57 so as to prevent flow through the smallermiddle orifice 59 while theplunger 50 is being inserted into thefirst container 20 but permit flow through the largerlower orifice 60 while theplunger 50 is being withdrawn from thefirst container 20. Thecheck valve 55 functions to permit theplunger 50 to build pressure within thefirst chamber 30 during insertion while abating the formation of a vacuum within thefirst chamber 30 during withdrawal.

The relative heights of theplunger 50 and thefirst chamber 30 are such that theupper orifice 58 in thesidewall 53 of theplunger 50 will remain in constant communication with the atmosphere. Positioning of theupper orifice 58 within thefirst chamber 30 would prevent flow from thefirst chamber 30 to the atmosphere and result in the creation of a vacuum within thefirst chamber 30 when theplunger 50 is being withdrawn from thefirst chamber 30 until theupper orifice 58 is moved out of thefirst chamber 30.

Aseal 29 is provided proximate the top 21 of thefirst container 20 to sealingly engage thesidewall 53 of theplunger 50.

Thefirst container 20,second container 40, andplunger 50 may be constructed from any suitable structural material including wood, metal and plastic with molded plastic constituting the material of choice. *** Thefilter 80 functions to remove both suspended solids and larger pathogens from the contaminatedwater 101. Removal of the suspended solids renders the water aesthetically agreeable and palatably acceptable. Generally, removal of those suspended solids which are visible to the naked eye (greater than about 40 microns) achieves the desired results. Removal of the larger pathogens is necessary because such pathogens are effectively resistant to chemical disinfection by the biocidallyeffective material 90. The larger pathogens generally resistant to chemical disinfection are cysts such as Giardia lamblia and Giardia muris which are typically about 6 microns in size. Because of the significantly smaller size of the pathogens which must be removed (6 microns) as compared to the suspended solids (40 microns), pathogen removal controls selection of thefilter media 80.

The United States Environmental Protection Agency recommends that microbiological water purifiers achieve at least a three-log (99.9%) reduction in the concentration of cysts such as Giardia lamblia and Giardia muris which are difficult to control by chemical means. Accordingly, thefilter media 80 employed in the present invention should be capable of ensuring at least a three-log reduction in the concentration of cysts such as Giardia lamblia and Giardia muris.

Thefilter 80 may be constructed from any porous material capable of providing the necessary cyst reduction, structural integrity and chemical compatibility including carbon block, ceramic, woven and nonwoven fiber, natural and synthetic membranes, and the like.

The biocidallyeffective material 90 may be any sufficiently porous, biocidally effective material capable of disinfecting contaminated water with a single pass. Examples of biocidally effective materials suitable for use in the present invention are disclosed in U.S. Pat. Nos. 4,238,477 and 3,817,860 issued to Lambert et al. Briefly, these references describe iodinated anion exchange resins, such a iodinated quaternary ammonium resins, which are effective for disinfecting contaminated water by percolation of the contaminated water through the resin.

The amount of biocidallyeffective resin 90 which should be employed within thesystem 10 depends upon a number of factors including the type and porosity of the biocidally effective resin, the configuration of the biocidally effective resin within thesystem 10, the rate of water flow through the system, and others. Generally, when an iodinated anion exchange resin is employed, the volumetric ratio of resin to water passing through the resin every second should be at least 2.5 and preferably at least 3.

Thefirst screen 27 may be constructed from any suitably porous material capable of retaining the biocidallyeffective material 90 and the optional active component(s) 95 in thelower portion 33b of the outerannular cavity 33 while permitting substantially unrestricted flow of potable water through thescreen 27. Thesecond screen 28 may be constructed from any suitably porous material capable of maintaining separation of the biocidallyeffective material 90 and the optional active component(s) 95 while permitting substantially unrestricted flow of potable water through thescreen 28. Suitable materials for use as the

screens

27,28 include woven and nonwoven fibers of plastic, glass or other material which is chemically compatible with the biocidallyeffective material 90.

A layer(s) of an active component(s) 95 may optionally be placed within thelower portion 33b of the outerannular cavity 33 downstream from the biocidallyeffective material 90 for achieving a desired effect upon thepurified water 103 such as a layer of activated carbon to remove undesirable tastes and odors, and/or a chelating agent to remove hardness ions from the purifiedwater 103. When a layer(s) of the optional active component(s) 95 is employed, a secondannular screen 28 should be placed between the layer of biocidallyeffective material 90 and the optional layer(s) of active component(s) 95 as well as between layers ofactive components 95 when multiple layers r of different active components are employed (not shown) to maintain separation of the

materials

90,95.

Thesystem 10 may be constructed to substantially any size but should generally provide a contaminatedwater 101 retention volume (displacement) defined by the first chamber upper portion 30A and the first chambercentral cavity subdivision 31 of about 0.05 to about 0.2 liters. Asystem 10 providing a displacement of less than about 0.05 liters is laborious to operate because of the number of strokes required while asystem 10 providing a displacement of greater than about 0.2 liters excessively cumbersome to transport and requires the use of significant energy to operate.

Atypical system 10 providing a displacement of about 100 ml requires about 4 to about 10 seconds to fully depress theplunger 50 when the lower portion of the first chamber is filled with contaminatedwater 101.

Depending upon several variables including the type of biocidallyeffective material 90 employed and the material of construction, asystem 10 providing a displacement of about 100 to 200 ml will typically weight about 300 to about 500 grams.

Depending upon various factors including the average pore size and porosity of thefilter 80, the average pore size and porosity of the biocidallyeffective material 90, and the number and type of additionalactive components 95, atypical system 10 should cause a pressure drop between thecentral cavity 31 and theoutlet orifice 35 in thefirst container 20 of about 5 to about 10 psig.

Operation

Referring to FIG. 3, operation of thesystem 10 includes the steps of (i) separating the first 20 and second 40 containers, (ii) withdrawing theplunger 50 from thefirst container 20, (iii) pouring a supply of contaminatedwater 101 into thefirst container 20 through the open top 21, (iv) opening theoutlet orifice 35 in thefirst container 20 by rotating thenozzle 70 from the parallel position to the transverse position, (v) positioning thesecond container 40 under theoutlet o orifice 75 in thenozzle 70, (vi) reinserting theplunger 50 into thefirst container 20, and (vii) applying pressure to the contaminatedwater 101 retained within thefirst container 20 by pushing theplunger 50 against the contaminatedwater 101.

Alternatively, steps (ii) and (iii) may be modified to (ii) depressing theplunger 50 completely into thefirst container 20, (iii)(a) pouring a supply of contaminatedwater 101 into theupper chamber 56 of theplunger 50 through theupper orifice 58 in the plunger 50 (preferably positioned through thehead 54 of the plunger 50), and (iii)(b) pulling upward on theplunger 50 so as to open the check-valve 55 and suction the contaminatedwater 101 retained within theupper chamber 56 of theplunger 50 into the first chambercentral cavity subdivision 31 and first chamber upper portion 30A.

The application of pressure to the contaminatedwater 101 retained within thefirst container 20 causes the contaminatedwater 101 to flow from thecentral cavity 31 through thefilter 80 and into the innerannular cavity 32. Thebaffle 26 then directs the filteredwater 102 in the innerannular cavity 32 down towards the annular passage 34 between thebaffle 26 and the bottom 22 of thefirst container 20. The filteredwater 102 passes through the annular passage 34 into thelower portion 33b of the outerannular cavity 33 where the filteredwater 102 percolates up through the biocidallyeffective material 90 and the activatedcarbon 95 retained within thelower portion 33b of the outerannular cavity 33. Thepotable water 103 then passes from thelower portion 33b of the outerannular cavity 33 through thescreen 27, into theupper portion 33a of the outerannular cavity 33, out of thefirst container 20 through theoutlet orifice 35 in thefirst container 20, into thenozzle 70 through theinlet orifice 74 in thenozzle 70, and out of thenozzle 70 through theoutlet orifice 75 in thenozzle 70.

Claims

I claim:

1. An apparatus for producing potable water from microbiologically contaminated water comprising:

(a) a first container having a first chamber for retaining contaminated water and a second chamber,

(b) a filter interposed between the first chamber and the second chamber such that an inner surface of the filter is in direct fluid communication with the first chamber and an outer surface of the filter is in direct fluid communication with the second chamber,

(c) a porous body of biocidally effective material disposed within the second chamber, and

(d) a plunger receivable within the first chamber and comprising means for forcing contaminated water retained within the first chamber through the filter and the porous body of biocidally effective material so as to microbiologically purify the contaminated water, and

(d) a means, in fluid communication with the first chamber, for abating the formation of a vacuum within the first chamber when the plunger is withdrawn from the first chamber and thereby reducing the return passage of fluid through the filter from the second chamber into the first chamber.

2. The apparatus of claim 1 wherein the apparatus defines a single, consolidated, compact body when operationally assembled.

3. The apparatus of claim 1 further comprising a second container comprising means for coupling with the first container to completely enclose the plunger.

4. The apparatus of claim 1 wherein the filter divides the first and second chambers so as to configure the first chamber as a substantially cylindrical cavity and configure the second chamber as a substantially annular cavity surrounding the first chamber.

5. The apparatus of claim 4 wherein the means for abating the formation of a vacuum within the first chamber comprises (i) a passage directly connecting the first chamber and the atmosphere, and (ii) a one-way valve within the passage which prevents fluid flow through the passage as the plunger moves in a first direction and permits fluid flow through the passage as the plunger moves in a second direction.

6. The apparatus of claim 5 wherein the one-way valve is effective for preventing fluid flow through the passage as the plunger is inserted into the first chamber and effective for permitting fluid flow through the passage as the plunger is withdrawn from the first chamber.

7. The apparatus of claim 5 wherein the passage extends through the plunger.

8. An apparatus for producing microbiologically potable water from contaminated water comprising:

(a) a first cylindrical container having an open end and an outlet orifice and defining an upper cylindrical chamber having a first diameter and a lower cylindrical chamber having a second diameter wherein the second diameter is greater than the first diameter,

(b) a cylindrical filter operably positioned within the lower cylindrical chamber of the first container so as to divide the lower chamber into a central cavity longitudinally aligned with the upper chamber and an annular cavity surrounding the central cavity,

(c) a cylindrical baffle dividing the annular cavity into an inner annular cavity and an outer annular cavity for directing flow downwardly through the inner annular cavity and upwardly through the outer annular cavity,

(d) a porous body of biocidally effective material operably positioned within the outer annular cavity, and

(e) a plunger sealably and reciprocally retained within the first container through the open end for forcing contaminated water retained within the central cavity through the filter, around the baffle, through the porous body of biocidally effective material, and out of the first container through the outlet orifice.

9. The apparatus of claim 8 wherein the apparatus defines a single, consolidated, compact body when operationally assembled.

10. The apparatus of claim 8 further comprising a second container comprising means for coupling with the first container to completely enclose the plunger.

11. The apparatus of claim 8 further comprising a means for abating the formation of a vacuum within the first container which comprises a longitudinal passageway through the plunger and a check-valve in communication with the passageway for sealing the passageway as the plunger is inserted into the container and for opening the passageway as the plunger is withdrawn from the container.